352 INHIBITION BY EXCITATION AND 



It is further very remarkable, that the positive kathodic polarisa- 

 tion in muscles veratrinised at one end is not only not impaired by 

 killing that end of the muscle during the existence of the state of ex- 

 citation there, but, as I had also previously observed in the muscle of 

 Anodonta, it very often increases considerably. 



Even directly after an action current produced by a momentary 

 excitation has passed away, it is possible at once to renew its power 

 of giving positive kathodic after-currents, in a muscle prepared 

 in the manner indicated. This may be done by killing the poisoned 

 fibre ends corresponding to the point of exit of the exciting current, 

 by crushing them with the forceps and compensating the strong 

 demarcation current produced thereby. By this procedure it is 

 well known that the production of a closing excitation is materially 

 prevented, while, as it appears, the results of the inhibitory actions 

 come into play as strongly after as before. However, before I 

 consider in detail the meaning of this phenomenon, which is sur- 

 prising at first sight, I must discuss some other facts which relate 

 to the existence of positive kathodic after-currents on exciting 

 electrically normal muscles that have not been poisoned. 



4. Positive kathodic polarisation in normal striated muscles. 



Hering 1 J who used exclusively muscle of R. esculenta, mentions 

 that sometimes in quite fresh muscles after the first excitation, 

 extremely feeble deflections of the magnet occur in the direction of 

 a positive kathodic polarisation, but he did not proceed to a more 

 detailed investigation of these trifling effects at that time. Since 

 then, on repeating similar experiments on preparations of the 

 sartorius of frogs (R. esculenta) which had been cooled in ice, 

 and the excitability of which had attained a very high degree, 

 I succeeded several times in getting stronger positive kathodic 

 effects, but they are still far less considerable than those which may 

 be observed under similar circumstances in preparations of R. tern- 

 poraria. 



Thus, on using the Edelmann galvanometer I was surprised that 

 normal sartorius preparations of R. temporaria, on being excited 

 with currents of medium strength and short period of closure, and 

 on leading off from the lower (kathodic) end, and from a correspond- 

 ing point of the middle of the muscle, gave at first very often 

 exclusively positive kathodic after-currents of considerable strength. 

 1 Sitzungsber. vol. Ixxxviii. p. 430. 



